Patients with suspected portal hypertension must first be evaluated by physical examination, upper digestive endoscopy and ultrasonography with Doppler. Moreover, the evaluation of patients with portal hypertension depends on the cause of portal hypertension, the presence of complications and the specific treatment considered. Haemodynamic assessment with measurement of the hepatic venous pressure gradient is useful in confirming the origin of portal hypertension. This technique is the 'gold-standard' for evaluating haemodynamic treatments. Splanchnic and systemic circulation must also be measured. Quantitative evaluation of the splanchnic territory by Doppler sonography and other non-invasive investigations, may be performed. Further clinical studies are, however, needed to determine their interest in portal hypertension.